Mon, 26 Jul 2010 14:25:56 -0700
6957438: improve code for generating warning messages containing option names
Reviewed-by: mcimadamore
1 /*
2 * Copyright (c) 2002, 2006, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
26 package com.sun.tools.javac.jvm;
28 import java.util.*;
30 import com.sun.tools.javac.code.Flags;
31 import com.sun.tools.javac.code.Symbol;
32 import com.sun.tools.javac.util.*;
34 /** The classfile version target.
35 *
36 * <p><b>This is NOT part of any supported API.
37 * If you write code that depends on this, you do so at your own risk.
38 * This code and its internal interfaces are subject to change or
39 * deletion without notice.</b>
40 */
41 public enum Target {
42 JDK1_1("1.1", 45, 3),
43 JDK1_2("1.2", 46, 0),
44 JDK1_3("1.3", 47, 0),
46 /** J2SE1.4 = Merlin. */
47 JDK1_4("1.4", 48, 0),
49 /** Support for the JSR14 prototype compiler (targeting 1.4 VMs
50 * augmented with a few support classes). This is a transitional
51 * option that will not be supported in the product. */
52 JSR14("jsr14", 48, 0),
54 /** The following are undocumented transitional targets that we
55 * had used to test VM fixes in update releases. We do not
56 * promise to retain support for them. */
57 JDK1_4_1("1.4.1", 48, 0),
58 JDK1_4_2("1.4.2", 48, 0),
60 /** Tiger. */
61 JDK1_5("1.5", 49, 0),
63 /** JDK 6. */
64 JDK1_6("1.6", 50, 0),
66 /** JDK 7. */
67 JDK1_7("1.7", 51, 0);
69 private static final Context.Key<Target> targetKey =
70 new Context.Key<Target>();
72 public static Target instance(Context context) {
73 Target instance = context.get(targetKey);
74 if (instance == null) {
75 Options options = Options.instance(context);
76 String targetString = options.get("-target");
77 if (targetString != null) instance = lookup(targetString);
78 if (instance == null) instance = DEFAULT;
79 context.put(targetKey, instance);
80 }
81 return instance;
82 }
84 private static Target MIN;
85 public static Target MIN() { return MIN; }
87 private static Target MAX;
88 public static Target MAX() { return MAX; }
90 private static Map<String,Target> tab = new HashMap<String,Target>();
91 static {
92 for (Target t : values()) {
93 if (MIN == null) MIN = t;
94 MAX = t;
95 tab.put(t.name, t);
96 }
97 tab.put("5", JDK1_5);
98 tab.put("6", JDK1_6);
99 tab.put("7", JDK1_7);
100 }
102 public final String name;
103 public final int majorVersion;
104 public final int minorVersion;
105 private Target(String name, int majorVersion, int minorVersion) {
106 this.name = name;
107 this.majorVersion = majorVersion;
108 this.minorVersion = minorVersion;
109 }
111 public static final Target DEFAULT = JDK1_7;
113 public static Target lookup(String name) {
114 return tab.get(name);
115 }
117 /** In -target 1.1 and earlier, the compiler is required to emit
118 * synthetic method definitions in abstract classes for interface
119 * methods that are not overridden. We call them "Miranda" methods.
120 */
121 public boolean requiresIproxy() {
122 return compareTo(JDK1_1) <= 0;
123 }
125 /** Beginning in 1.4, we take advantage of the possibility of emitting
126 * code to initialize fields before calling the superclass constructor.
127 * This is allowed by the VM spec, but the verifier refused to allow
128 * it until 1.4. This is necesary to translate some code involving
129 * inner classes. See, for example, 4030374.
130 */
131 public boolean initializeFieldsBeforeSuper() {
132 return compareTo(JDK1_4) >= 0;
133 }
135 /** Beginning with -target 1.2 we obey the JLS rules for binary
136 * compatibility, emitting as the qualifying type of a reference
137 * to a method or field the type of the qualifier. In earlier
138 * targets we use as the qualifying type the class in which the
139 * member was found. The following methods named
140 * *binaryCompatibility() indicate places where we vary from this
141 * general rule. */
142 public boolean obeyBinaryCompatibility() {
143 return compareTo(JDK1_2) >= 0;
144 }
146 /** Starting in 1.5, the compiler uses an array type as
147 * the qualifier for method calls (such as clone) where required by
148 * the language and VM spec. Earlier versions of the compiler
149 * qualified them by Object.
150 */
151 public boolean arrayBinaryCompatibility() {
152 return compareTo(JDK1_5) >= 0;
153 }
155 /** Beginning after 1.2, we follow the binary compatibility rules for
156 * interface fields. The 1.2 VMs had bugs handling interface fields
157 * when compiled using binary compatibility (see 4400598), so this is
158 * an accommodation to them.
159 */
160 public boolean interfaceFieldsBinaryCompatibility() {
161 return compareTo(JDK1_2) > 0;
162 }
164 /** Beginning in -target 1.5, we follow the binary compatibility
165 * rules for interface methods that redefine Object methods.
166 * Earlier VMs had bugs handling such methods compiled using binary
167 * compatibility (see 4392595, 4398791, 4392595, 4400415).
168 * The VMs were fixed during or soon after 1.4. See 4392595.
169 */
170 public boolean interfaceObjectOverridesBinaryCompatibility() {
171 return compareTo(JDK1_5) >= 0;
172 }
174 /** Beginning in -target 1.4.2, we make synthetic variables
175 * package-private instead of private. This is to prevent the
176 * necessity of access methods, which effectively relax the
177 * protection of the field but bloat the class files and affect
178 * execution.
179 */
180 public boolean usePrivateSyntheticFields() {
181 return compareTo(JDK1_4_2) < 0;
182 }
184 /** Sometimes we need to create a field to cache a value like a
185 * class literal of the assertions flag. In -target 1.4.2 and
186 * later we create a new synthetic class for this instead of
187 * using the outermost class. See 4401576.
188 */
189 public boolean useInnerCacheClass() {
190 return compareTo(JDK1_4_2) >= 0;
191 }
193 /** Return true if cldc-style stack maps need to be generated. */
194 public boolean generateCLDCStackmap() {
195 return false;
196 }
198 /** Beginning in -target 6, we generate stackmap attribute in
199 * compact format. */
200 public boolean generateStackMapTable() {
201 return compareTo(JDK1_6) >= 0;
202 }
204 /** Beginning in -target 6, package-info classes are marked synthetic.
205 */
206 public boolean isPackageInfoSynthetic() {
207 return compareTo(JDK1_6) >= 0;
208 }
210 /** Do we generate "empty" stackmap slots after double and long?
211 */
212 public boolean generateEmptyAfterBig() {
213 return false;
214 }
216 /** Beginning in 1.5, we have an unsynchronized version of
217 * StringBuffer called StringBuilder that can be used by the
218 * compiler for string concatenation.
219 */
220 public boolean useStringBuilder() {
221 return compareTo(JDK1_5) >= 0;
222 }
224 /** Beginning in 1.5, we have flag bits we can use instead of
225 * marker attributes.
226 */
227 public boolean useSyntheticFlag() {
228 return compareTo(JDK1_5) >= 0;
229 }
230 public boolean useEnumFlag() {
231 return compareTo(JDK1_5) >= 0;
232 }
233 public boolean useAnnotationFlag() {
234 return compareTo(JDK1_5) >= 0;
235 }
236 public boolean useVarargsFlag() {
237 return compareTo(JDK1_5) >= 0;
238 }
239 public boolean useBridgeFlag() {
240 return compareTo(JDK1_5) >= 0;
241 }
243 /** Return the character to be used in constructing synthetic
244 * identifiers, where not specified by the JLS.
245 */
246 public char syntheticNameChar() {
247 return '$';
248 }
250 /** Does the VM have direct support for class literals?
251 */
252 public boolean hasClassLiterals() {
253 return compareTo(JDK1_5) >= 0;
254 }
256 /** Does the VM support an invokedynamic instruction?
257 */
258 public boolean hasInvokedynamic() {
259 return compareTo(JDK1_7) >= 0;
260 }
262 /** Although we may not have support for class literals, should we
263 * avoid initializing the class that the literal refers to?
264 * See 4468823
265 */
266 public boolean classLiteralsNoInit() {
267 return compareTo(JDK1_4_2) >= 0;
268 }
270 /** Although we may not have support for class literals, when we
271 * throw a NoClassDefFoundError, should we initialize its cause?
272 */
273 public boolean hasInitCause() {
274 return compareTo(JDK1_4) >= 0;
275 }
277 /** For bootstrapping, we use J2SE1.4's wrapper class constructors
278 * to implement boxing.
279 */
280 public boolean boxWithConstructors() {
281 return compareTo(JDK1_5) < 0;
282 }
284 /** For bootstrapping, we use J2SE1.4's java.util.Collection
285 * instead of java.lang.Iterable.
286 */
287 public boolean hasIterable() {
288 return compareTo(JDK1_5) >= 0;
289 }
291 /** For bootstrapping javac only, we do without java.lang.Enum if
292 * necessary.
293 */
294 public boolean compilerBootstrap(Symbol c) {
295 return
296 this == JSR14 &&
297 (c.flags() & Flags.ENUM) != 0 &&
298 c.flatName().toString().startsWith("com.sun.tools.")
299 // && !Target.class.getSuperclass().getName().equals("java.lang.Enum")
300 ;
301 }
303 /** In J2SE1.5.0, we introduced the "EnclosingMethod" attribute
304 * for improved reflection support.
305 */
306 public boolean hasEnclosingMethodAttribute() {
307 return compareTo(JDK1_5) >= 0 || this == JSR14;
308 }
309 }